U.S. patent application number 11/316134 was filed with the patent office on 2007-06-21 for roller separator for printers.
Invention is credited to Gary Neal Hackney.
Application Number | 20070138732 11/316134 |
Document ID | / |
Family ID | 38172555 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070138732 |
Kind Code |
A1 |
Hackney; Gary Neal |
June 21, 2007 |
Roller separator for printers
Abstract
Rollers or drums of a printer may be separated to prevent damage
from continued contact, for example, during shipping. In some
embodiments, operation of at least one of the rollers or drums
during normal printer operation de-activates the separator. For
example, the separator may rotate from a first position, in which
it maintains a separation, to a second inactive position where the
separator allows the two components to contact for a normal
operation.
Inventors: |
Hackney; Gary Neal;
(Georgetown, KY) |
Correspondence
Address: |
LEXMARK INTERNATIONAL, INC.;INTELLECTUAL PROPERTY LAW DEPARTMENT
740 WEST NEW CIRCLE ROAD
BLDG. 082-1
LEXINGTON
KY
40550-0999
US
|
Family ID: |
38172555 |
Appl. No.: |
11/316134 |
Filed: |
December 21, 2005 |
Current U.S.
Class: |
271/10.09 |
Current CPC
Class: |
G03G 15/0216 20130101;
G03G 2215/0119 20130101 |
Class at
Publication: |
271/010.09 |
International
Class: |
B65H 5/00 20060101
B65H005/00 |
Claims
1. A method comprising: separating two printer elements prior to
operation of the printer; and automatically contacting said
elements in response to printer operation.
2. The method of claim 1 including using a separator to separate
first and second printer elements, said separator including a first
section to engage said first printer element and a second section
to disengage said first printer element, a distance from the center
of an axle of a second printer element to the first section is
greater than the radius of the second printer element and a
distance from the center of the axle to the second section is less
than the radius of the first printer element.
3. The method of claim 2 including providing a handle on said
separator.
4. The method of claim 2 including providing a finger-shaped
protrusion to arrest the rotation of said separator.
5. The method of claim 1 including providing a separator which is
mounted on the axle of one of said elements and which engages the
other of said elements to maintain a separation between said
elements.
6. The method of claim 1 including separating a fixed roller and a
movable roller.
7. The method of claim 6 including separating a photoconductive
drum from a roller.
8. The method of claim 7 including separating a photoconductive
drum from a charge roll.
9. The method of claim 1 including providing a separator which is
movable between an active separating orientation and a de-active
non-separating orientation.
10. The method of claim 9 including providing a separator which is
rotatable between said orientations.
11. A separator for a printer comprising: a first portion mountable
on an axle of a first rotatable printer element; a second portion
to abut against the surface of a second rotatable printer element,
said second portion including a first section and a second section,
a distance from the center of an axle of a first printer element to
the first section is greater than the radius of the first printer
element and a distance from the center of the axle to the second
section is less than the radius of the first printer element,
enabling said separator to rotate around said axle when the printer
element, abutted against said second portion, rotates, to remove
the separation between said elements.
12. The separator of claim 11 including a finger-shaped portion
coupled to said first portion and forming a free end of said
separator.
13. The separator of claim 12 including a handle coupled to said
separator.
14. The separator of claim 11 wherein said separator is rotatable
between a first position separating the printer elements and a
second position allowing the printer elements to contact.
15. A printer comprising: a fixed roller; a movable roller; and a
separator between said fixed and movable rollers to separate said
fixed roller from said movable roller prior to operation of said
printer, and upon operation of the printer to automatically allow
said rollers to contact each other.
16. The printer of claim 15 wherein said separator to rotate from a
first orientation, separating said rollers, to a second orientation
in response to operation of at least one of said rollers.
17. The printer of claim 15 wherein said fixed roller is a
photoconductive drum.
18. The printer of claim 17 wherein said movable roller is a charge
roll.
19. The printer of claim 15 wherein said printer is an
electrophotographic printer.
20. The printer of claim 15 wherein one of said rollers includes an
axle, said separator to rotatably mount on said axle to rotate
between a first position maintaining the separation between said
rollers and a second position allowing said rollers to contact.
Description
BACKGROUND
[0001] This invention relates generally to printers and,
specifically, to devices for separating the rollers thereof prior
to actual use.
[0002] Generally, in electrophotographic printers it is desirable
to separate various rollers and drums. For example, some rollers
and drums will chemically attack other rollers and drums when
maintained in unmoved contact for long periods of time, especially
at higher temperature and humidity conditions. This chemical attack
may result in defects in a printed page. In other cases, one roller
may end up being softer than another roller and may develop flat
spots over time.
[0003] The time period involved for such damage varies with the
chemistry and environment but may sometimes be on the order of six
to eight weeks. Frequently, the shipping and shelf life of a
product prior to application and use at the end customer exceeds
this period. Moreover, the uncontrolled temperatures during
shipment can accelerate the chemical reaction.
[0004] To avoid these types of problems, electrophotographic
products are generally shipped with various rollers separated from
each other with customer removable separating devices. Those
devices may be made of plastic, paper, or other materials. During
the unpacking and set up of the product, the customer is instructed
to remove these separating devices and dispose of or recycle them.
The product will not function correctly if these devices are not
removed.
[0005] One place where such a separator may be utilized is between
a charge roll and a photoconductor drum. Generally, in use, the
charge roll is spring loaded against the photoconductor drum. A
removable separating device fits on each end of the charge roll,
holding it away from the drum. The two ends of the separator are
connected by a handle or strap to make sure that both ends are
removed by the customer.
[0006] Thus, there is a need for better ways to maintain the
separation between various rollers and drums prior to actual use of
electrophotographic devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a cross-sectional depiction of one embodiment of
an electrophotographic printer;
[0008] FIG. 2 is an enlarged, cross-sectional view of one
embodiment of the present invention prior to use; and
[0009] FIG. 3 is an enlarged, cross-sectional view corresponding to
FIG. 2 in the ready to use configuration in accordance with one
embodiment of the present invention.
DETAILED DESCRIPTION
[0010] Referring now to the drawings and, more particularly, to
FIG. 1, there is shown one embodiment of an electro-photographic
device 10 in which embodiments of the present invention may be
applied. Of course the present invention is in no way limited to
any specific printer design and may be applicable to a variety of
different printer arrangements.
[0011] The device 10 includes laser print heads 12, 14, 16, and 18,
a black toner cartridge 20, a magenta toner cartridge 22, a cyan
toner cartridge 24, a yellow toner cartridge 26, photoconductive
drums 28, 30, 32, and 34, an intermediate transfer belt 36, and a
controller 37. In one embodiment, the controller may be a
combination of application specific integrated circuits,
microprocessors, and firmware suited to the tasks of printing
documents.
[0012] Each of the laser print heads 12, 14, 16, and 18 projects a
respective laser beam 38, 40, 42, and 44 off a respective one of
the polygonal mirrors 46, 48, 50, and 52. As each of the polygonal
mirrors 46, 48, 50, and 52 rotates, it scans a respective one of
the reflected beams 38, 40, 42, and 44 in a scan direction,
perpendicular to the plane of FIG. 1, across a respective one of
the photoconductive drums 28, 30, 32, and 34.
[0013] Each of the photoconductive drums 28, 30, 32, and 34 may be
negatively charged, for example, to approximately -1000 volts, and
is subsequently discharged to a lower level, such as approximately
-300 volts, in the areas of the peripheral surface that are
impinged by a respective one of the laser beams 38, 40, 42, and
44.
[0014] During each scan of a laser beam across the photoconductive
drum, each photoconductive drum 28, 30, 32, and 34 is continuously
rotated, for example, in a clockwise direction, in a process
direction indicated by the arrow 54. The scanning of the laser
beams 38, 40, 42, and 44 across the peripheral surface of the
photoconductive drums is cyclically repeated, thereby discharging
the areas of the peripheral surfaces on which the laser beams
impinge.
[0015] The toner in each of the toner cartridges 20, 22, 24, and 26
is negatively charged and is transported upon the surface of a
developer roll 80 and biased, for example, to approximately -600
volts. Thus, when the toner for the cartridges 20, 22, 24, and 26
is brought into contact with the respective one of the
photoconductive drums 28, 30, 32, and 34, the toner is attracted to
and adheres to the portions of the peripheral surfaces of the drums
that have been discharged to the lower voltage, say -300 volts, by
the laser beams.
[0016] As the belt 36 rotates in the direction indicated by the
arrow 56, the toner from each of the drums 28, 30, 32, and 34 is
transferred to the outside surface of the belt 36. As a print
medium, such as paper, travels along the path 58, the toner is
transferred to the surface of the print medium and nip 62.
[0017] Referring to FIG. 2, a fixed roller, such as a
photoconductive drum 28, may rotate in the direction R. Prior to
application and use, the drum 28 may be held in a separated
position from a charge roll 25, for example. A separator 200 is
responsible for maintaining the charge roll 25 and the drum 28 in a
fixed spacing. While an embodiment is illustrated involving the
maintenance of a separation between a fixed roller, such a
photoconductive drum, and a spring loaded roller, such as a charge
roll 25, other rollers and drums may use separators 200 as
well.
[0018] The separator 200 may have a closed complex shape, including
a first end 204, which rests against the drum 28. The first end 204
may be finger shaped and may be connected to a convex portion 210.
The convex portion 210 has a larger radius of curvature than charge
roll 25. A second convex portion 212 has a smaller radius of
curvature than charge roll 25. The distance from the center of the
axle 215 about which the separator rotates to the surface of
portion 210 is larger than the radius of charge roll 25, and the
distance from the center of the axle 215 to the surface of portion
212 is smaller than the radius of charge roll 25.
[0019] A handle 206 couples the portions 204 and 212. The handle
206 includes an upstanding section coupled to a U-shaped portion
214 which journals the axle 215 of the charge roll 25 in one
embodiment.
[0020] In use, the spring 208 biases the charge roll 25 against the
photoconductive drum 28. Prior to use, for example during shipping,
the drum 28 and the roll 25 may be separated by the separator 200.
The separation is achieved by the larger radius of the portion 210,
held in position by the finger-shaped first end 204.
[0021] When the printer is operated, the photoconductive drum 28
rotates in the direction of the arrow R. This rotation of the drum
28 causes clockwise rotation of the separator 200 to the position
shown in FIG. 3. In other words, the rotation of the drum 28 causes
the portion 210 to act like a roller and to rotate approximately
90.degree. to the position shown in FIG. 3.
[0022] The rotation of the separator 200 ends when the portion 212
is juxtaposed from the drum 28. Due to its smaller radius of
curvature, the portion 212 ends up being spaced away from the drum
28. The rotation of the separator 200 in the direction indicated by
the arrow S is arrested by the stop 202. In this position, a spring
208 presses the charge roll 25 against the drum 28.
[0023] In some embodiments, the separation is automatically
eliminated at the right time--the time when the printer is being
operated. As a result, there is no need for the user to be forced
to remember to remove, not only one separator, but both separators
between each pair of separated components.
[0024] While it typically may not be necessary, if for any reason
it is thereafter desired to re-separate the drum 28 and roll 25,
all that needs to be done is to rotate the handle portion 206 back
to the position shown in FIG. 2, immediately reestablishing the
desired separation. For example, this re-separation may be done
before shipment or storage.
[0025] In some embodiments of the present invention, a separator
may be less expensive than conventional separators. Moreover, the
separator may be easily snapped onto the shaft of the moveable
roller. Also, in some cases, no customer action or intervention is
required. Likewise, nothing need be discarded and the separator is
available for future use if ever needed. In some embodiments, the
friction between the U-shaped portion 214 of the separator 200 and
the axle 215 of the spring loaded roll 25 may be sufficient to
maintain the separator in the position shown in FIG. 3 without
moving, rattling, or shaking.
[0026] In some embodiments, two separators can be used on each of
two opposed ends of two rollers or drums to be separated.
[0027] References throughout this specification to "one embodiment"
or "an embodiment" mean that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one implementation encompassed within the
present invention. Thus, appearances of the phrase "one embodiment"
or "in an embodiment" are not necessarily referring to the same
embodiment. Furthermore, the particular features, structures, or
characteristics may be instituted in other suitable forms other
than the particular embodiment illustrated and all such forms may
be encompassed within the claims of the present application.
[0028] While the present invention has been described with respect
to a limited number of embodiments, those skilled in the art will
appreciate numerous modifications and variations therefrom. It is
intended that the appended claims cover all such modifications and
variations as fall within the true spirit and scope of this present
invention.
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